A pallet is a portable, horizontal, rigid, platform used as a base for assembling, storing, stacking, handling goods as a unit load. Conventional pallets are typically constructed of wood and are made by stapling or nailing a number of boards (known as "deckboards") at their ends to a number of continuous solid boards (known as "stringers"). The upper set and lower set (where used) of deckboards thereby form an open area defined by the thickness of the stringers. This opening is used to accommodate a fork lift or hand truck. In this way the pallet may be moved from place to place by lifting the pallet and its load off the floor.
The vast majority of all pallets used in the U.S. are constructed of wood, but wood pallets have many disadvantages. Labor and material costs for wooden pallets have increased faster than inflation. Because of their expense, the pallets are often reused or returned to their place of origin. The cost of returning empty pallets to their owners is obviously high. Additionally, The average weight of a wooden pallet is about forty pounds. Since shipping costs are usually tied to the weight of the goods shipped, the cost of shipping is increased by the weight of the pallet. Indeed, pallets are sufficiently heavy that smaller warehouse workers are able manually to move the pallets only with some difficulty. Wooden pallets are often damaged during use and, because of the pallet cost, must be repaired if possible or disposed of. Depending upon the industry involved, pallets may be used between two and four times before they are disposed of. Disposal of any solid materials including broken pallets is an increasingly difficult and costly problem.
The invention is a pallet constructed of paper or other lightweight sheet materials and includes a central platform or deck constructed of a honeycomb filler bounded on the bottom surface by a continuous corrugated sheet which covers the supporting legs or runners so to form a continuous cover over the entire bottom surface. The upper surface of the central platform may be covered with a corrugated sheet or heavy sheet stock. Additionally, the upper and/or lower sheets may be folded over the edges of the honeycomb core and fastened to their opposite sides. The runners or legs which are included to support the central platform are cut to transform the two-way pallet to a four-way design. One or more specifically conformed bottom sheets are then adhesively mounted to the bottomside of the pallet to strengthen and reinforce it. In addition to the inherent strength and low cost of the finally assembled pallet, by careful selection of construction materials, the design may be completely recycled as paper without separation into constituent parts.
There are a number of pallet designs which are made mostly of paper. For instance, U.S. Pat. No. 3,661,099, to Shelor, shows a paper shipping pallet having a deck having a core section made of small strips cut from single, double, or triple wall corrugated paper board sheet stock glued face to face. Sheets of corrugated are glued to the longitudinal edges of the composite core. The core and facing sheets are desirably of a specific size of corrugated sheets, i.e., having a size "A" flute or better. The legs of the pallet appear to be wooden blocks.
U.S. Pat. No. 3,650,459, to Tucker, shows a paper pallet design involving a folded corrugate sheet as the cargo support area. That cargo deck is provided with a number of pallet feet (which operate as spacer blocks within the cargo deck) made of molded plastic material such as polystyrene. The use of a honeycomb core within the cargo support area is not disclosed.
U.S. Pat. No. 3,952,672, to Gordon et al, shows a disposable pallet made of a single folded corrugated sheet. The use of a honeycomb core on the cargo support area is not disclosed.
U.S. Pat. Nos. 4,867,074 and 5,001,991, to Smith, each show a pallet design in which the cargo deck is made up of a large number of girders folded from corrugated sheet and assembled with a series of cross girders. The use of a honeycomb core in the cargo support area is not disclosed.
U.S. Pat. No. 4,790,249, to Webb, shows a pallet design in which the cargo deck is made up of facing sheets separated by a number of blocks having a specific design. The block design involves a cellulosic material glued together by a bonding material (such as ureaformaldehyde) all extruded into the shape of a box beam. The boxes are positioned so to protect the deck from the tines on a fork lift.
Netherlands Patent Application 83-00024 shows an interesting design for a paper pallet. The cargo support deck appears to be constructed of a number of loops of paper glued together at a number of sites within the deck and also glued to a periphery forming the edge of the deck. Neither the use of a honeycomb core nor the use of corrugated sheet in the cargo deck support area is disclosed.
There are few disclosures showing the use of honeycomb materials in the core of the cargo support deck.
One such disclosure is Published U.K. Patent Application 2,213,462-A to Green et al. This published application shows a paper pallet design in which the cargo deck is made up of two face sheets of, e.g., corrugated cardboard and having a an open structure such as a paper or card honeycomb between them. It is said that the deck may be raised from the floor using feet of similar construction. The deck core is made to be penetrable by the tines of a fork lift. The disclosure is silent on the use of a corrugated sheet folded over the edge of the central core and fastened to the opposite side.
U.S. Pat. No. 4,319,530, to Moog, discloses a pallet, said to be disposable, having a cargo supporting deck area made up of a central core of a honeycomb made of laminated corrugate. The core is faced with one or more corrugated sheets glued to the core. The facing on the cargo support surface of the central core may be made up of multiple layers of corrugated sheets. The disclosure is silent on the use of a corrugated sheet folded over the edge of the central core and fastened to the opposite side nor, obviously, is any benefit accorded such a folded sheet.
None of these disclosures show a pallet constructed of paper involving a central platform or deck constructed of a honeycomb filler bounded on the top and bottom surfaces by corrugated sheets nor do these disclosures show the feature of increased physical stability due to the integration of the lower surface as support for the central platform. Finally, none of these publications show the production of a four-way pallet by the modification of a two-way pallet in the manner specified herein nor do these publications show the structure of the resulting device.